Which paper is about GJK-EPA by Nathanael Presson ?

Please don't post Bullet support questions here, use the above forums instead.
Post Reply
Jack2016
Posts: 10
Joined: Fri Aug 12, 2016 5:46 am

Which paper is about GJK-EPA by Nathanael Presson ?

Post by Jack2016 »

Nathanael said the algorithm is incremental convex hull,
but I can't find paper

btGjkEpa2.cpp:
EPA::Evaluate()

Code: Select all

					
m_status = eStatus::Valid;
for (; iterations < EPA_MAX_ITERATIONS; ++iterations)
{
	if (m_nextsv < EPA_MAX_VERTICES)
	{
		sHorizon		horizon;
		sSV*			w = &m_sv_store[m_nextsv++];
		bool			valid = true;
		best->pass = (U1)(++pass);
		gjk.getsupport(best->n, *w);
		const tbScalar	wdist = dot(best->n, w->w) - best->d;
		if (wdist>EPA_ACCURACY)
		{
			for (U j = 0; (j < 3) && valid; ++j)
			{
				valid &= expand(pass, w,
					best->f[j], best->e[j],
					horizon);
			}
		       if (valid && (horizon.nf >= 3))
			{
				bind(horizon.cf, 1, horizon.ff, 2);
				remove(m_hull, best);
				append(m_stock, best);
				best = findbest();
				if (best->p >= outer.p) outer = *best;
			}
			else { m_status = eStatus::InvalidHull; break; }
		}
		else { m_status = eStatus::AccuraryReached; break; }
	}
	else { m_status = eStatus::OutOfVertices; break; }
}
User avatar
Erwin Coumans
Site Admin
Posts: 4221
Joined: Sun Jun 26, 2005 6:43 pm
Location: California, USA
Contact:

Re: Which paper is about GJK-EPA by Nathanael Presson ?

Post by Erwin Coumans »

The Expanding Polytope Algorithm (EPA) is by Gino van den Bergen. See "Proximity Queries and Penetration Depth Computation on 3D Game Objects" link/pdf and his book from this page:

http://www.dtecta.com/publications

Nathan implement this, as well as some improvements.
Jack2016
Posts: 10
Joined: Fri Aug 12, 2016 5:46 am

Re: Which paper is about GJK-EPA by Nathanael Presson ?

Post by Jack2016 »

Erwin Coumans wrote:The Expanding Polytope Algorithm (EPA) is by Gino van den Bergen. See "Proximity Queries and Penetration Depth Computation on 3D Game Objects" link/pdf and his book from this page:

http://www.dtecta.com/publications

Nathan implement this, as well as some improvements.
Thanks a lot ,Erwin
Post Reply